(function() {
    abstract class Animal {
        name:string;
        constructor(name:string) {
            this.name = name;
        }
        abstract say():void;
    }
    
    class Dog extends Animal {
        say() {
            console.log("我叫"+this.name)
        }
    }
    let dog1 = new Dog('旺财a');
    console.log(dog1,'dog1')
    dog1.say()
})()